<span>Risks of emphysema, asthma and cancer are associated with the tars and hydrocarbons in inhaled smoke. The tar acts to coat the bronchial sacs, in effect causing the bronchial sacs to be damaged beyond repair and suffocating the smoker over time. The hydrocarbons contain cancer causing chemicals that enter the blood stream and are carried throughout the body.</span>
D. Organisms have cells with different shapes and functions.
Answer:
Ligand-receptor interaction is the first interaction that triggers cell signalling.
Ligands are the hormones, drugs or neurotransmitters that specifically bind with receptors present in cell surface to initiate cell signalling. Ligand binding to the receptor is reversible. Binding of the ligand to the receptor can activate or inactivate receptor. Activation may lead to cell signalling pathways. Inside cells, there are secondary molecules which on activation starts a cascade of reactions. which in-turn regulate the function of the ligand molecule.
At first, the activated receptor relates with G proteins molecules in the cell.
before the ultimate physiological effect of the ligand on the cell's behavior is produced Therefore, the cellular signaling starts as soon as the first messenger (the ligand) binds to its receptor.
hope this helps
Answer:
It is copied.
Explanation:
Replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules.
